The use of membranes to effect separation of gas/gas, liquid/liquid, and liquid/solid mixtures and solutions has achieved general industrial applicability by various methods, among them being ultra filtration, hyper filtration, reverse osmosis, and dialysis. In general, membrane elements associated with these processes are contained in vessels called modules, comprising a shell having various inlet and outlet ports and having an assembly of membranes within said shell, means for collecting permeate which passes through the membranes and emerges on their downstream faces and means for keeping permeate materials from comingling. The internal configurations are so arranged as to permit the introduction of the feed stream with or without pressure on the upstream face of the membranes.
Commonly assigned U.S. Pat. No. 4,207,192 discloses a hollow filament separatory module and a method of fabrication generally related to the invention disclosed herein. However, it will be realized by those familiar with the art that the teachings herein are equally applicable to various other membrane configurations.
In prior art devices separatory module shells have generally comprised a cylindrical shell enclosing the hollow separatory fibers and spaces for flow paths for the fluid to be separated. Various materials have been used in composition of these pressure shells in order to accommodate the exceedingly high pressures involved in hollow fiber separation techniques. These pressures are commonly on the order of 200 to 2000 psi. Occasionallly pressures as high as 5000 have been contemplated. The shells are generally closed at their ends by plates of sufficient strength to withstand the high internal pressures employed in the separation process. The plates may be secured to the shells by various means such as by bolts embedded in shell ends. Alternatively, the walls of the pressure shell may be expanded at their ends to provide means for installing retaining rings or the like. In other variations of the prior art the ends of the pressure shells have grooves machined into their inner surface to accommodate split circle elements or snap rings.